We will continue studies of the interactions between inflammatory cells and fibroblasts to determine how these interactions alter fibrobplasia, collagen synthesis and collagen degradation. Specifically, "thick-thin" epon sections of human keloid, prior to and after intralesional corticosteroid therapy, will be used to monitor changes in the ratio of fibroblasts to inflammatory cells. In addition, changes in the various inflammatory cell types will be quantitated (mast cells, macrophages, lymphocytes, etc.). Other analyses will determine if increased collagen synthesis in keloid is due to an increased number of fibroblasts, increased collagen synthesis per cell, or both. Similar studies will be made using the open rat wound mode following either systemic or local administration of corticosteroids. Fibroblasts in tissue culture will be used to test stimulation and/or depression of cell division and collagen synthesis by keloid extracts or burn patient serum. Keloid pathogenesis studies will be continued to determine the effect of corticosteroids on collagenase activity and these finding will be correlated with alterations in tissue alpha globulin levels. Other studies will determine if keloid formation is the result of an auto-immune process. We will determine if there are antibodies against collagen in keloid patients' serum and if native collagen or collagen breakdown products are chemotactic for lymphocytes from keloid patients.